The Neuroimaging Core has been a part of the MRDDRC since the Center was first established, in 1987. The Core was initially under the directorship of Dean Wong, M.D., Ph.D. Reflecting both Dr. Wong's areas of expertise as well as the prevailing neuroimaging techniques at the time, during its first five years of operation the Neuroimaging Core focused substantial resources on development and refinement of positron emission tomography (PET) methods for qualitative and quantitative assessments of CMS neurotransmitter receptors. Over the next five years, as reflected in the 1993 resubmission for the second five-year funding period, the number of radioligands in use or under investigation had increased, and included ligands that could be used to assess receptors for opiates, for dopamine, for benzodiazepines, and for serotonin. While the Core also facilitated access to expertise in anatomic MRI and magnetic resonance spectroscopy (MRS), these areas were less well represented then they are now. MRS was largely constrained to spatially rather coarse single voxel studies, and spatial co-registration of multiple anatomic MRI studies to common templates for the purposes of quantifying morphologic differences between brains or for localizing lesions to specific regions was in its relative infancy